So staight to the issue. My box temp was around 14°C (57°F) when the mechanical thermostat was on setting 6 which was completely unacceptable. So I cranked it up to 7 (the highest setting) and that brought the box temp down to 9°C (48°F). Still not cold enough. I hear people easily get 5°C (41°F) temps or lower in their fridge. OK, now I am in the tropics and the ambient temperature is always 27-30°C (81-86°F) so I know it would be a struggle. But even on setting 7 the duty cycle of the compressor was only about 50%. Maybe a bit more.

So recently I pulled into a marina and now I'm on shore power. The fridge is 12V so it's running off the batteries but I read on the forum somewhere to try jumping terminals C-T on the control module to test to see what the limits of the system in combination with the insulation are. Well now the fridge is running 100% of the time but the lowest temp in the box is still about 9°C (48°F) and in the worst location is 14°C (57°F). I'm shooting temps with a laser temp gun.

So, yeah, that's the situation. I would have thought running all the time the temperatures would go lower but that doesn't seem to be the case here (weird). The evaporator is completely iced over on the outside (quite evenly) and shooting the temp of items in the icebox show 0°C (32°F).

My question is this: What do I need to do to have a normal fridge with normal, even, and cold temperatures inside it that draws in the neighborhood of 50Ah per day or less? Because I'm ready to drag this friggin' Frigoboat off the end of the dock.

On setting 7 I estimated 66Ah/day and it wasn't nearly cold enough.

I've already examined the galley to see how hard it would be to access the fridge and neighbouring icebox from underneath/behind to insulate them better but it appears to be next to impossible without tearing out the countertops. Everything is glued in this Beneteau 423 and would involve tearing off the fiddles and counter and then re-doing them. Ouch.

Any advice is greatly appreciated. Especially from Rich Boren or Richard Kollmann.

Can you provide some more details of your system. Emotion is optional. These systems are not black magic. They are simply unfamiliar to most refrig specialists. They are what I would label as eutectic. They only operate when everything is in spec.

Sounds like you need a repairman to evacuate the old coolant, then recharge the system with new coolant. Have the repairman check your system for leaks prior to refilling. You probably have low pressure in the coolant system where there's enough to ice up the evaporator, but the system as a whole isn't working efficiently.

Sounds like you're losing cold pretty fast. How thick is the insulation in the box? Is this new or existing problem? air cooled, keel cooled? water cooled? How big is the box compared to the plate? is this OEM or an owner add-on?

I can't tell how thick the insulation is because, believe it or not, there is no access to behind the fridge. The galley is in a corner and the whole end is walled off.

I have owned the boat for a year and a half and to tell you the truth, until we started cruising full time about 3 months ago, I never noticed the box temp as being low because we mostly used the fridge for drinks and the odd snack food but I always knew it wasn't cold enough. Now that we're living on the boat, this is unacceptable as food spoils a lot faster.

It's an air cooled unit. I believe OEM and insulation also OEM from 2004 so it's probably not doing it's job anymore either.

Evaporator makes an icebox big enough to fit two bags of mixed vegetables in. Tiny for a freezer. The fridge is decent sized. Probably OEM so properly sized.

Thanks for the advice guys. Kenomac, I will probably do as you say and bring in a tech now. Assuming they can just refill the system, I imagine it's probably going to be a hog on power because it seems the insulation is shot based on the fairly large temperature differentials I'm seeing when shooting different spots on the walls.

Sounds like you have a typical marinerefrigeration problem . Box to big , poor insulation , evaporator plate to small . So basically there is more heat getting in the box then you are taking out . A Hvac guy will not be able to help . He will probably just over charge the system , and you, then leave . There is no short or easy answer . Options are , rebuild box for better R value , or add more heat removalequipment . You could install a larger system or another complete system in the box , but you will need the power to drive it . Refrigeration is a large problem in the tropics manly because of poor insulation and watercooling , good you have air cooling .

Sounds like you have a typical marine refrigeration problem . Box to big , poor insulation , evaporator plate to small . So basically there is more heat getting in the box then you are taking out . A Hvac guy will not be able to help . He will probably just over charge the system , and you, then leave . There is no short or easy answer . Options are , rebuild box for better R value , or add more heat removalequipment . You could install a larger system or another complete system in the box , but you will need the power to drive it . Refrigeration is a large problem in the tropics manly because of poor insulation and water cooling , good you have air cooling .

Like I wrote earlier, we had the same issue with our Figo system for three months, same symptoms with the evaporator icing up but not creating enough cold. There wasn't enough coolant in the system, some had leaked out, or not enough had been put in. The tech evacuated and recharged the system, and now everything is fine.

Why would you suggest completely rebuilding the box before attempting the cheapest and most likely needed repair?

insulation is shot based on the fairly large temperature differentials I'm seeing when shooting different spots on the walls.

And likely the maximum cooling capacity was barely adequate to begin with...

Quote:

Originally Posted by chala

It all depend what you call “iced over”. A good evaporator should not be covered with ice and if icing, the ice should melt off during the off cycle. Faulty seals are the main cause of icing.

But I am not Rich Boren or Richard Kollmann.

But you are Rich in helpfulness!

An evaporator cannot work as designed when iced over... It is not a cold plate... You would have pretty much the same fridge box temps if you had a block of ice in the freezer box with the system off...

Quote:

Originally Posted by typhoon

Sounds like you have a typical marine refrigeration problem . Box to big , poor insulation , evaporator plate to small . So basically there is more heat getting in the box then you are taking out .

And iced over evap...

Quote:

Originally Posted by a64pilot

Wait a minute, way I read it is he has temps of 0 in the icebox. Is this a spill over system?
Also by jumping the terminals you may have it running continuously, but maybe in it lowest speed?

Spill is what we're reading...

__________________In the harsh marine environment, something is always in need of repair...

BlackAdder no doubt your insulation is next to useless on a factory box. Also the seals are probably allowing leakage. Try using some tape to seal all the edges of the box while closed then leave it overnight and check your temps the next day. Probably a big difference. Don't jump to hiring a refrigeration tech, as he can't fix your problem. Anyway there is only one guy in St Maarten who knows what he is doing when it comes to A/C or refrigeration now that all the small companies have been bought out and you probably won't know him. Using anyone else will be a complete waste of money.

it would be very helpful to know three things, the size of the evaporator plate or (or bin) if it's wrapped into a freezer bin), the compressor model (BD35, BD50, other) and the cubic feet of the box. If the compressor is indeed frosting the entire plate it's totally possible that the system is undersized for the box and never actually did work. Before you spend money on tech service let's be sure we have the right products installed.

OK what I'm saying is if you have 0 degrees in the freezer section, that is colder than average so maybe you just don't have enough air circulation to cool the fridge half.
I'm guessing average freezer temp is closer to 10 degrees F. Mine on a good day will only get to about 5

it would be very helpful to know three things, the size of the evaporator plate or (or bin) if it's wrapped into a freezer bin), the compressor model (BD35, BD50, other) and the cubic feet of the box. If the compressor is indeed frosting the entire plate it's totally possible that the system is undersized for the box and never actually did work. Before you spend money on tech service let's be sure we have the right products installed.

Agree Agree
Sounds like he has a bin evaporator. , just big enough for two bags of frozen veggies .
The insulation is twenty years old and from the original builder "Beneteau" . They never had enough insulation to begin with! And in the tropics!! No way around it . More insulation !!